The $^{1}\mathrm{S}_0$-$^{3}\mathrm{P}_2$ magnetic quadrupole transition in neutral strontium

TL;DR

This paper investigates the ultranarrow magnetic quadrupole transition in neutral strontium, demonstrating its potential for quantum simulation, quantum computation, and single-site addressing in optical lattices through high-resolution spectroscopy and experimental validation.

Contribution

It provides detailed spectroscopic data and a proof-of-principle experiment showing the transition's use for local addressing in optical lattices, advancing quantum technology applications.

Findings

Measured the absolute transition frequency as 446,647,242,704(2) kHz.

Observed an isotope shift of +62.91(4) MHz between $^{88}$Sr and $^{87}$Sr.

Demonstrated local addressing with a resolution of 494(45) nm in an optical lattice.

Abstract

We present a detailed investigation of the ultranarrow magnetic-quadrupole $^{1}\mathrm{S}_0$-$^{3}\mathrm{P}_2$ transition in neutral strontium and show how it can be made accessible for quantum simulation and quantum computation. By engineering the light shift in a one-dimensional optical lattice, we perform high-resolution spectroscopy and observe the characteristic absorption patterns for a magnetic quadrupole transition. We measure an absolute transition frequency of 446,647,242,704(2) kHz in $^{88}\mathrm{Sr}$ and an $^{88}\mathrm{Sr}$-$^{87}\mathrm{Sr}$ isotope shift of +62.91(4) MHz. In a proof-of-principle experiment, we use this transition to demonstrate local addressing in an optical lattice with 532 nm spacing with a Rayleigh-criterion resolution of 494(45) nm. Our results pave the way for applications of the magnetic quadrupole transition as an optical qubit and for single-site addressing in optical lattices.